Remotely adjustable control



Feb. 24, 1942. A. B. NEWTON i REMOTELY ADJUSTABLE CONTROL Filed Dec. 16, 1959 Patented Feb. 24 1942 PATENT OFFICE 2.214.254, nEMo'rELY ADJUSTABLE coN'raoL Alwin B. NewtomMinneapolis, Minn., assigner to Minneapolis-Honeywell Regulator Company, Minneapolis, Minn., a corporation of Delaware Application December 16, 1939, Serial No. 309,625 4 Claims. 01. 137-156) The present invention relates to control devices V and particularly to a remote adjusting arrangement for such a device. While the usual temperature. pressure, or 'humidity control devices are adjustable as to control point and are suitable for the requirements of most installations, it is often desirable to locate the control device in an inaccessible position. Under such circumstances it is desirableA to provide a remote adjustment of the control point of the device. For example, modernl airconditioning units, particularly room type units, are provided with a decorative housing enclosing the control devices as well as the air conditioning apparatus. Here it is especially desirable to provide a remote adjustment on the exterior of the housing for adjusting the control devices located in the interior of the housing. v

Accordingly, the prime object of this invention is to provide a condition responsive control de.

vice the control point of which may be adjusted from a point remotely located with respect to the control device proper.

More specliically, the object of 'this invention is to provide a condition responsive control device having an adjusting spring remotely llocated from the control device and connected thereto .in a manner which permits the adjusting spring to be located at any remotepoint with respect to the controller. This may be accomplished by connecting the remotelylocated adjusting spring to the control device through the medium of a hydraulic transmission utilizing a ilexible tube for transmitting the force of the adjusting springy tothe'control device.

Further lobjects will -be apparent from the Y specication, claims, and from the single4 figure of the drawing which showsva remotely adjustable pressure responsive control device partly inV section. f

`For purposes of illustrationxthe invention is4 shown-as incorporated in a pressure responsive A -control device whichmay be controlling the com-l pressor motor of a compression refrigeration sys- Y. act-on bellows I5 and raise or lower 'the lower portion of the bellows due to exing oi' the bellows. f l

A vertically extending rod I8 transmits movement of bellows I6 to the left hand end oflever I8 to rotate saidv lever about a knife edge 2l which is suitably secured in casing III. Avverti- `in volume oi the other.

cally-extending arm 22 is xedly attached to lever I8 to operate a' mercury switch 25. Mercury switch 25 is irictionally pivoted in casing III onl a pin 2,8 so that it will remain in any position it has been movedto by armv 22., Biiurcated end 28 oi.' the arm 22 is adapted to actuate mercury switch 25 through a pin' 30. It will be noted that the distance between the bifurcated portions 28 is greater than the diameter of pin 30 in order to provide a differential between the pressures which will open and close the circuit through the mercury switch 25. l

A ilexible metallic bellows 33 is supported at its lower end inthe casing I0 ona block 34 I which is rigidly attached to the caslngxl. The upper end of the bellows 33 is operatively conthereof which is connected to the bellows 33 by means of a flexible tube 4 I Bellows 33, bellows 40, and tube 4I are completely filled with any suitable non-compressible liquid such as'oil so that a decrease in the volume of either bellows will result in a like increase The elements associated with casing in and the pipe I4 may be located adjacent the refrigeration mechanism while the parts of the remote adjusting device 38 may be located at any convenient point such as ona control panel or on the surface of the decorative housing of a unit air conditioner where it will be readily accessible. Such a panel 45 has secured thereto a frame 46 to the right -hand end of which the bellows 48 is suitably attached bybellows and limits its expansion.

' A cone 5I is secured to the left hand end of bellows `4|! to transmit movements of bellows 40 toa-lever 53 which is pivoted at 54 on .two ears 55 which may be formed as part ofthe frame 46.

I A stop 52 formed as part ofthe frame 46 cooperates withv the lower end -oflever 53 to prevent excessive .compression of the bellows 40. Directly opposite the cone 5I with respect to lever 53 is aV similar cone 58 which also bears lupon lever 53 and transmits the force exertedby a spring 80 through lever 53 to the bellows 4,0. The spring isheld in place by a spring retainer 6| which carries the cone 58 and by a spring retainer 62 which is attached to the right hand end of an adjusting screw 85, the purpose oi which is to be set forth hereinafter. A manual adjusting 60 knob Il is mounted on a shaft 68 vwhich extends through the panel 45. To the lower end of the shaft 68 is secured a gear wheel 10 which is adapted to cooperate with another gear wheel 12. Gear 12 consists of a plate having radial slots therein suitably spaced to cooperate with the teeth onthe gear 1li'.`y A stop 'I3 on gear 12 cooperates with a stcp'14 on the frame 46 to limit the movement of gear 12 and consequently the available range of adjustment. Gear 'I2 is pivoted in the frame 46 on a pin 11 and has rigidly attached thereto a cup shaped member 19 which also carries at its right hand end a nut 80. A screw 82 is carried in the nut 80 but is prevented from rotating with nut 80 by an arml 83 which extends through a slot 85 in the frame 46. The screw 65 which carries the spring retainer 62 is carried by the screw 82 and may be adjusted therein for the purpose of changing the tension on spring 60 to calibrate the device.

It will be seen from the arrangement of the parts-that by turning the adjusting knob 61, gear 12 is correspondingly turned by gear "Il to angularly position the nut 8l). The screw 32 is thereby moved to the right or left to position the left hand end of the spring 6l.

In operation it will be seen 'that an increased pressure in the pipe Il will be transmitted through the tube I2 to'compress the bellows I6 and rotate the lever I9l aboutthe knife edge 20 in a clockwise direction. The right hand end of the lever I3 will be lowered to compress the bellows 33 through the yoke 36 and force liquid out of the bellows into tube II. From thetube 4I the liquid will be forced into the bellows 40 and result in an expansion thereof to move cone 5I to the left. 'I'he lever 53 will be rotated slightly in a clockwise direction and the spring 60 will be compressedil Thus spring 60 -resists movement of the lever I9 so that the position of lever I9 will be determined by the force of spring 60 in combination with the pressure acting on the bellows I6. The pressure at which the mercury switch will be actuated therefore depends on the adjustment of spring 60. Hence for each setting of the manual control knob 61 which determines the tension of the spring 60 there will be a corresponding pressure acting on bellows I6 which will actuatethe mercury switch 25.

In order that the range of adjustment of the manual control knob 61 will be suitable 'to cover the range of adjustment desired, the adjusting screw 65 associated with the spring retainer 62 is provided. Thusl if suitable indications are pended claims.

I claim as my invention:

1. In a condition responsive device, in combination, a first expansible envelope the pressure in which depends on the value of a variable condition, a pivoted lever a rst portion ofv which is operatively connected to said envelope, control means adapted to be actuated by said lever on rottion thereof, a second expansible envelope the volume of which is changed by movements of said lever, said second expansible envelope being operatively connected to a second portion of said lever, a third expansible envelope, a tube connecting said second and third envelopes and a substantially' noncompressible liquid nlling said second and third envelopes and said tube. a spring tending to reduce the volume of said third envelope and manually operable means for adjusting the tension of said spring for adjusting the control point of the device.

2. In a remotely adjustable condition responsive controller, in combination, a condition responsive element, control means adapted to be actuated by said element, a rst ex`pansible envelope, a spring remotely located from said eiement and tending at al1 values of the condition to reduce the volume of said first envelope, a second expansible lenvelopaadapted to control the eilect of said condition responsive element on said control means, a exible tube connecting said first and second envelopes, a rst screw threaded means rotation of 4which adjusts the tension of said spring, and a second screw threaded means for varying the relationship between said flrst screw threaded means and said spring, thereby calibrating the setting of said first screw threaded means. d

3. In a remotely adjustable condition responsive controller, in combination', a condition responsive element, control means adapted to be actuated by said element, a ilrst expansible eriplaced adjacent the knob761, the knob may be set` to indicate a certain temperature and screw 65 adjusted until the device actually controls at that temperature. Another adjusting screw 31 is provided between the lever I9 and the yoke 36, as previously mentioned. By means of this adjustment 'it is possible to adjust the relation between bellows 33, bellows 40, and the lever I9 so that the available range of movement of the biellws `will cover the range of adjustment des re From the foregoing description it will be seen that a remote adjusting arrangement has been provided for a condition responsive device which may be located at any desired point with respect velope, a spring remotely locatedfrom said element and tending at all values of thecondition ,to reduce the volume of said rst envelope, a

lsecond expansible envelope adapted to control l of said spring.

to the switch or other control means utilized. It

will be understood that a temperature responsive element could be substituted for the pressure responsive bellows I6. Likewise, a humidity responsive element could serve as ^the condition responsive means. I am not to be limited by the 4, In a remotely adjustable condition responsive controller, in combination, a condition responsive element, control means adapted to be actuated by said element, a first expansible envelope, a lspring remotelylocated from saidfelement and tending at all lvalues of the condition to reduce the volume of said first envelope, a pivoted lever extending between said first expansible envelope and said spring, said lever acting as al 4guiding abutment for both said first expansibleenvelope and said spring, a second expansible envelope adapted to control the eect of said condition responsive element on said control means, a flexible tube connecting said flrst and second envelopes. and manual means for adjusting the tension of said spring.

ALWIN n. 

